Breechblock for explosively actuated fastening tools



Aprii 24, 1951 .s. A. TEMPLE BREECHBLOCK FOR EXPLOSIVELY ACTUATEDFASTENING TOOLS Filed July 19, 1946 V D m V v%/0\ EW? IN VEN TOR..STQNLE 4. TEMPLE ATTORNEYS Patented Apr. 24, 195i orrics BREECHBLOCKFOR EXPLOSIVELY ACTUATED FASTENING TOOLS Application July 19, 1946,Serial No. 684,935

7 1 Claim. 147) This invention relates to the insertion of fasteners. Ithas to do particularly with explosive propelled fastenings for attachingmountings in a masonry construction.

Heretofore one way of inserting or aflixing fastenings in walls, floors,ceilings, etc., of concrete or the like has involved forming a hole inthe body of concrete, generally by means of a star drill and hammer,after which an expanding bolt is inserted and expanded to grip the sidesof the hole. This is a tedious and expensive procedure.

The mounting of fastenings in metal plates by means of an explosivecharge has been known for a. considerable time. Evidently it was assumedby workers in the art that such a method could not be employed withrespect to concrete and like bodies upon the theory that such a bodywould be shattered by the force of the impact. I have discovered thatsuch isnot the fact, and that on the contrary if the explosive charge beproperly selected for a given set of conditions the fastening will betightly embedded in the concrete body, and to the depth desired. Sinceconcrete is not fluid in character and cannot flow as can metal, andhence cannot be bulged out by a projectile, it is natural to assume thatit must necessarily be shattered when a projectile is fired into it.What actually happens is not known with certainty, but I believe thatgreat heat is generated instantaneously as the projectile penetrates theconcrete body and that under this heat, combined with the heavy pressureexerted by the explosive charge, the concrete immediately surroundin theprojectile is rendered plastic, its porosity eliminated, and thematerial compacted to make room for the projectile as its pointed endenters the body. The resulting grip of the compacted concrete upon theprojectile is exceedingly strong, being much superior in this respect tothe grip of an expansion bolt.

Asalient object of the invention relates to the improvement of a breechblock for use in explosively actuated fastener driving tools in whichthebreech block construction is such as to permit the breech block to beinserted either end foremost in the breech end of the barrel of thetool.

Other objects and features of novelty will appear as I proceed with thedescription of those embodiments of the invention which, for thepurposes of the present application, I have illus trated in theaccompanying drawing, in which Fig. 1 is a side View, partly in section,of a projectile embedded part way in a concrete wall, the enlarged andthreaded head of the projectile extending outwardly from the wall.

Fig. 2 is a side view of the same projectile in its original conditionbefore being placed in a. tool and fired.

Fig. 3 is a similar view of a projectile with an. internally threadedhead in its original unfired. condition.

Fig. 4 is a side view partly in section of theprojectile of Fig. 3 afterit has been fired from a tool and is embedded in a masonry body, with athreaded eye-bolt mounted in the embedded pro-- jectile.

Fig. 5 is a side View, partly in section of an unthreaded projectilefired into a concrete wall. through one flange of an angle iron forsecuring: the latter to the wall, and

Fig. 6 is a view, principally in central longi-- tudinal section, of atool for firing any of the: illustrated projectiles.

Referring now to the drawing, II] is the barrel. of a tool designed forfiring the projectiles illustrated. Barrel I0 is provided with a bore IIand. a counterbore I2, the latter running out at theinner end of thebarrel. In the counterbore I 2 I mount a breech block I3 provided with abore to fit a blank cartridge I4 of standard size. Both.

.ends of the breech block I3 have counterbores I5 in order that theflange I6 of the cartridge may be inserted flush with the end of thebreech block. This arrangement permits the block to be inserted in thebarrel either end foremost.

The externally threaded projectile of Fig. 2 and the internally threadedprojectile of Fig. 3 are provided at their rear ends with outwardlyextending annular flanges i! and I? respectively which are adapted tobear against the shoulder formed at the junction of the bores II and I2of the tool. With this flange in place between this shoulder and thebreech block the latter stands flush with the inner end of barrel It.

The head I8 of the externally threaded projectile has an undercut I9extending a substantial distance along the projectile in front of theflange I1, and forwardly of this undercut the balance 'of the head I8 isthreaded as shown at 20. The

external diameter of the threaded portion 20 is such that it fitsslidably within the bore H of the tool and serves to guide theprojectile in its forward travel through the bore from the position ofFig. 6 to the flared end 2! of the bore. When the cartridge I i isexploded pressure builds up behind the projectile until it reaches avalue suflicient to sever the flange II, after which the projectile isdriven out of the tool, the severed flange [1 remaining temporarily inthe tool. The flange is severed or broken away from the projectile closeto the undercut I9 because its circle of minimum length occurs there,but the break is not necessarily a clean and smooth one. Usually a roughedge 22 is left on the projectile, as indicated in Fig. 1. This edgehowever is of less diameter than the root diameter of the threads ofthreaded portion 20, and hence offers no obstruction to the applicationof a nut or other internally threaded member to be attached to theembedded projectile.

The internally threaded projectile of Fig. 3 has a smooth head 24 of thesame diameter as the external diameter of the threaded portion 20 of theprojectile of Fig. 2. Head 24 therefore fits slidably Within the bore llof thetoo'l and flange ll engages the shoulder between bores l and l l.When this projectile is in place in the tool and the cartridge behind itis exploded flange I1 is sheared off quite cleanly along aouter surfaceof the metal object. When attach- 1 ment of the metal object to thebody'is the only requirement the head of the projectile need not bethreaded. In other cases where it i desired to provide a smooth surfaceon' a rough wall and to fasten some object thereto, a metal plate suchas 25 of Fig. 1 may be held againstthe'wall and an externally threadedprojectile fired therethrough into the wall, as shown in that figure.

Fig. 4 illustrates one use of an internally threaded projectile. Herethe cartridge selected is one having a charge of such strength that theentire projectile is forced into the wall flush with the exteriorsurface thereof. projectile is driven into the wall only until the headthereof engages the exterior surface. either event the internal threads35 may receive an externally threaded stud of any desired type,

as for example an eye-bolt 3i, and this bolt may be held against turningby a lock nut 32. Objects of various kind may be hung from suchasupport.

In Fig. 5 I have shown the invention applied to the problem of securingan angle iron 80 to a concrete or other masonry wall. In this case thehead iii of the projectile is not threaded. The angle iron is heldagainst the wall by a helper and the operator fires the projetcilethrough a flange of the angle iron, the projectile coming to a stop whenthe shoulder 62 of the projectile head 5| strikes the angle iron.Structural steel of other cross-sections may of course be secured to awall, floor or ceiling by the same means.

The tool for firing these projectiles, other than 'With respect to theparts abovedescribed, may be ofany desired construction. That hereinillustrated comprises a carrier 35 that is removably threaded at 36 tothe rear end of barrel l0, and is provided with an end surface 3'! thatabuts against the barrel and provide a backing for breech block I3 and'thefla'nged end of cartridge 14.- In order to facilitate the connectionand disconnection of the-barrel Ill and carrier 35,

these parts are knurled as indicated at 3B and 39.

In addition the outer end of barrel Ill may be providedwithspann'erwrench holes 40. When a In other cases the dischargedcartridge is to be removed and the tool reloaded, the operator separatesbarrel II] from carrier 35 by unscrewing it. He then shakes loose anddrops out of the barrel the breech block i3, the exploded cartridge I4and the severed projectile flange IT or H", puts a new projectile intothe bore ll until the flange H or ll thereof engages the shoulder at thejunction of the two bores II and i2, then inserts the breach block l3either end foremost and finally puts a new cartridge into the breechblock, after which the barrel I0 is again threaded into the carrier 35.

As shown herein carrier 35 has a bore 42, 43', in which is mounted afiring pin 44 that is normally held 111* retracted position by a coilspring 45. A sleeve 46 provided with a, handle 41 is mounted to slideupon carrier 35, and may be" held against rotation by a pin 48 mountedin the carrier cooperating with a slot 49 in the sleeve. A centrallydisposed plunger 50 rigid with the sleeve 46 is pushed vigorouslyforward by one hand of the operator whose other hand grasps the barrelIi], thereby causing the firing pin to set' off the cartridge. Coilspring 52 normally holds the sleeve 46 in retracted position.Theforwardend of the barrel may be provided with a'conical guard 55 forc'uttingoff flash from the cartridge when the tool is discharged.

It will be appreciated that projectiles of the kinds illustrated, andothers having heads of the proper diameter to fit within the bore of thetool, may be embedded in masonry bodiesvery'rapidly as compared with theconventional means of mounting fastenings in such bodies. Thedisconformed with considerable dispatch, and the mounting of theprojectile in the masonry body is then of course instantaneous.Consequently various brackets, plates, fastenings .and the like may besecured to buildings of concrete or other masonry with rapidity and atsmall cost. The projectiles are'formed of steel and are preferablypointed, as shown.

Having thus described my invention, I claim:

In a tool of the character described, a barrel having a bore for guidingthe projectile, said barrel having acounterbore adapted to receive aflange on a, projectile, a breech blockof uniform external diameterslidably mounted in said counterborefor engagement with said flange,said breech block having a central bore for the reception of a flangedblank cartridge .and'being counterbored at both ends for the receptionof the cartridge flange, whereby said breech block may be insertedeitherend first, backing means for the outer end'of said breech block, andmeans for firing said cartridge.

STANLEY A. TEMPLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

